LED light sources have advantages of high luminous efficiency, low heat generating, energy saving and long span-life, and thus are widely used. Light generated by single LED light source is low, and thus needs a plurality of LED light source to be packaged together to improve optical flux for lighting. The LED light sources mounted together generate a lot of heat. The heat concentrates in small spaces and is difficult to dissipate. If temperature of the LED is too high, illumination of the LED will decay rapidly, finally life-span of the LED lamp is greatly shortened.
For reducing working temperature of the LED lamp, COB-type LED lamp is disclosed in the art with LED light sources directly fixed on an end surface of a heat transfer substrate of the LED lamp, and the heat transfer substrate is thermally connected to a heat sink of the LED lamp. However, such COB-type LED lamp reduces overheating just by improving heat conductivity, and heat dissipation thereof depends only on the heat sink under the heat transfer substrate, ways for heat dissipation is single, heat dissipation efficiency is limited, and thus may still unable to reduce the working temperature of the LED lamp.